Light projecting device



P. F. EARLY Sept. 13, 1949.

LIGHT PROJECTING DEVICE 2 Sheets-Sheet 1 Filed Nov. 4; 1944 INVENTOR.

Arron/vs Y P. F. EARLY LIGHT PROJECTING DEVICE Sept. 13, 1949.

2 Sheets-Sheet 2 Filed NOV. 4, 1944 INVENTOR.

PA UL PEARL Patented Sept. 13, 1949 LIGHT PROJECTING DEVICE Paul F. Early, Dayton, Ohio, assignor to Standard-Thomson Corporation, a corporation of Delaware Application November 4, 1944, Serial No. 561,855

3 Claims. 1

This invention relates to a light projecting device and more particularly to a device of the type known as a cockpit lamp, which is designed more particularly for use on military aircraft but is not limited to such use. The present application is a continuation in part of my pending application filed October 16, 1943, Serial No. 506,482, now Patent No. 2,404,476, dated July 23, 1946.

In the operation of aircraft at night it is important that there should be at least suflicient illumination within the same to render the instrument panel visible and to enable other instrumentalities to be observed and operated, and in the operation of military aircraft it is equally important that there should be no light in or on the same which would be visible to enemy aircraft or from the ground when operating over enemy territory. It has been proposed heretofore to equip military aircraft with a lamp or lamps which can be adjusted to provide a diffused or floodlight illumination when such illumination is not objectionable and, when concealment is necessary, to provide a concentrated beam, or spotlight, which can be confined to a particular instrument or other restricted area which is to be illuminated.

It is one object of the invention to provide such alight projecting device of improved construction and operation.

A further object of the invention is to provide such a device which can be quickly and easily adjusted to provide the desired illumination and. which will be automatically retained in its adjusted position.

A further object of the invention is to provide such a device in which maximum adjustment may be effected by a relatively small movement of the adjusting element.

A further object of the invention is to provide such a device in which the projected beam is sharply defined and free from stray rays of light.

A further object of the invention is to provide such a device in which the light within the defined pattern is of uniform intensity and free from dark sections, such as the image of the lamp filament.

A further object of the invention is to provide such a device with operable means for reducing the brilliancy of the projected light which can be mounted within the device and can be actuated from the exterior thereof without interfering with the illumination adjusting means.

Other objects of the invention may appear as the device is described in detail.

In the accompanying drawings Fig. 1 is a longitudinal section taken lengthwise of a device embodying the invention and partly broken away; Fig. 2 is a longitudinal sectional view taken through the forward end of the device on the line 2-2 on Fig. 1 and partly in top plan; Fig. 3 is a detail view of the filter and its operating mechanism; Fig. 4 is a perspective view of the contact unit forming part of the means for connecting the lamp with an exterior source of electric current; Fig. 5 is an inverted view of the unit of Fig. 4; Fig. 6 is a transverse section taken on the line 66 of Fig. 1 omitting the cable connection; Fig. '7 is a longitudinal section taken through another embodiment of the invention; Fig. 8 is a perspective view, partly broken away, of the body member of the device of Fig. 7; Fig. 9 is a perspective view, partly broken away, of the key element of Fig. '7; and Fig. 10 is a perspective view, partly broken away, of the lens supporting member of Fig. 7.

In these drawings I have illustrated two embodiments of the invention, each of which comprises a tubular structure in or on which are supported the lamp, the controlling means for the lamp, the focusing lens and their associated parts. This structure includes a tubular body member, which is normally stationary and by which the movable elements are supported, a supporting member for the focusing lens which is axially adjustable with relation to the stationary member, and an adjusting device which is preferably rotatable about the longitudinal axis of the stationary member and is so connected with the stationary member and the lens supporting member, by screw threads or otherwise, that the rotation of the adjusting device will impart axial movement to that device with relation to the stationary member and will cause the lens supporting member to move axially with the adjusting device and with relation thereto. Thus the lens supporting member moves a greater distance than the adjusting device moves, thereby enabling the relatively large axial movement to be imparted to the lens supporting member by a small rotary movement of the adjusting device. It is to be understood, however, that these embodiments have been chosen for the purpose of illustration only and the light projecting device as a whole, as well as the several parts thereof, may take various forms and may be operated in various ways without departing from the spirit of the invention.

In that embodiment of the invention shown in Figs. 1 to 6 the tubular body member H extends for the major portion of the length of the projecting device as a whole and is substantially cylindrical in form. Mounted in the body member is means, such as a lamp socket l2, for supporting the lamp i 3, the lamp socket being in the present instance provided with a reflector M. The lens supporting member I5 is tubular in form and has a substantially cylindrical portion adapted to extend into the forward end of the body member Il and of an external diameter substantially less than the internal diameter of the adjacent portion of the body member ll. At its forward end the lens supporting member has an inwardly extending annular part it pro, viding an opening I! of relatively small diameter to receive a focussing lens H}. The lens is mounted on a seat [9 in the part l6 and is retained on said seat by a snap ring 26. The cylindrical part of the lens supporting member which extends to the rear of the lens has an internal diameter substantially larger than the diameter of the opening I! and is provided with rearwardly extending projections or arms 21 having longitudinal slots 22 into. which extend pins 23 carried by screws 24 mounted in the respective sides of the body member ll, so that the lens supporting member is held against rotation with relation 'tothe body member but is free to move axially with relation thereto. Arranged between the forward portion of the body member and the lens: supporting member is an adjusting device 25 which is tubular in form and which has screw threaded connection with the body member, as shown at 26, and with the lens supporting member, as shown at 21, whereby the rotation of the adjusting member will cause the same to move axially with relation to the body member and will cause the lens supporting member to move axially with the adjusting member and with relation thereto so that the lens supporting member will move a distance substantially greater than the distance the adjusting device moves. The adjusting device has a part arranged exteriorly of the body member by means of which it may be rotated and, as here shown, this part comprises a thickened portion 28 at the forward end of the adjustingdevice which is provided with a knurled or ribbed outer surface. A leaf spring 29' seated in a groove 38 in the lens supporting member bears against the unthreaded portion of the inner surface of the adjusting device and frictionally holds the latter against rotation until positive force is applied thereto. It will be apparent therefore that the focussing lens can be moved from one limit to the other limit of its movement with relation to the lamp It b relatively small rotary movement of the adjusting device and that the lens and its supporting member are automatically retained in the positions to which they have been moved. It will be noted that the threaded connection 21 between the lens supportingmember l5 and the adjusting member 25 terminates a substantial distance from the outer ends of those members so as to provide the two members with smooth cylindrical bearing surfaces, and that the adjusting member and the body member II are also provided with cylindrical bearing surface between the threaded connection 26 and the enlarged head 23 of the adju tin memb r- The l ngths of h s b a n urfa es are uch that. the l ns suppo ting member can be moved to the outer limit of its adiustment without. exposin h threads on any f said members. This, is important when precision adjustment is required, because the accumula.-

tion of dust or other foreign matter on exposed threads would result in excessive wear on the threads during subsequent adjustments.

When the light is transmitted directly from the lamp to the focussing lens the image of the lamp filament will appear upon the pattern defined by the projected light and this is often highly 0bjectionable, particularly when the light rays have been concentrated to form a. light pattern, or spotlight, of a relatively small diameter. To eliminate this image from the projected light pattern I utilize collecting lenses to concentrate the rays of light from the lamp into a compact form or beam in advance of the f-ocussing lens and then slightl difluse the concentrated rays before the enter the focussing lens. The means for accomplishing this result may take various forms but in order to adapt the same for use in a light projecting device of the type here shown I have mounted within the tubular structure a cylindrical shell 3| which, in the present instance, has an open rear end into which the lamp it: extends and a front end wall 32 having a small diameter light opening 33 in axial alinement with the focussing lens 18. This shell may be mounted in the tubular structure in any suitable manner but preferably it is provided at its rear end with a radial flange 34 which is secured to inwardly extending projections or blocks secured to and preferably formed integral with the body member ll, one of the blocks being shown at 35 to which the flange is attached by a screw 36. The flange is provided with openings 34" through which the projections 21 on the lens. supportin member may pass. Mounted within this shell are three l nses. 3L 3? and. 39. The lenses may be mounted within the shell and secured in pron- .er relative positions therein in any suitable manner. In the present instance, the front surface of the lens 39' fits snugly against the end wall 32v of the shell, which is shaped to conform to the front surface of the lens. The lenses are re: tained in. proper spaced relation one to the other by spacin sleeves 40. The first collecting lens. :3!- partially condenses the rays of light from the lamp and transmits the same to an intermediate portion of the second collecting lens 38. hi h further condenses the rays and transmits the same. E0 the central portion of the third lens 39 from which they are transmitted through the li t pe in 33 to the. focussing lens l8. The desired diffusion of the concentrated rays of light, is preferably effected by leaving one of the adjacent surfaces of the lenses 38 and 39, preferably the forward surface of the lens 38, in an unpelished or partially polished condition. This provides s filcient difiusion of the concentrated rays. o ect the elimination of the filament image without appreciably modifying the character of the projected light.

In; many installations it is desirable that. means he provided formaterially subduine the brilliancy of the projected light, this being best accomplished by means of a light filter interposed in the path of the projected light. In this. form of the device I have shown means for movably supporting the light filter within the tubular structure itself adjacent to the focussing len and for moving the same into and out of the path of the light from the collecting lenses. The filter itself preferably comprises a disk of translucent material, such as red glass or plastic, a shown at 41. In the particular arrangement here shown, the fi e i is Carried by a holder 42 in the nature of a small plate having an Opening therethrough and means for supporting the disk: in line wi h that opening. The disk and its filter are supported for movement between the end wall 32 of the shell 3| and a transverse plate or guard 43 which is supported in fixed spaced relation to the end wall 32 and has an opening 44 in line with and preferably somewhat larger than the light opening 33 of the shell. The opening 44 is extended upwardly and the plate 43 also has a forwardly extending part t5 forming a channel through which the filter disk may move into and out of alinement with the light opening 33, the lower edge of this part 45 being concentric with the light opening 33 and cooperating with the lower portion of the opening 44 to form a circular opening. The opening 44 is extended upwardly above the part 45, as shown at 46, to permit the disk to extend through the same and into the channel formed by the part 45.

The disk holder 42 is preferably pivotally supported and, as here shown, is provided with openings through which extend the forward ends of levers 41 which are pivotally supported adjacent their rear ends on the shell. In the present instance, a strip of metal 48 extends rearwardly from the lower edge of the plate 33 and i provided at its rear end with curved arms 49 which extend upwardly on opposite sides of the shell and which are rigidly connected with the shell, as by soldering the same to the shell or to the flange 34. The strip 48 supports the plate 33 and the upper end of that plate is of reduced width and is bent rearwardly above the shell, as shown at 50, so as to carry the upper end of the opening M rearwardly and permit the disk to project through the same when the latter is in its elevated or inoperative position. The levers ii are connected one with the other for movement in unison about a common axis and, as here shown, they are pivotally mounted on the upper ends of the arms 59 and are connected one to the other by. a yoke 5! which extends about the upper portion of the shell. The levers are preferably yieldably supported in their uppermost positions to retain the filter disk in its inoperative position and a suitable actuating device is provided for moving the levers and therefore the filter from one position to another and for retaining the same in the positions to which they have been moved. .As here shown, a fiat spring 52 is secured to, and preferably formed integral with, the yoke 5! and extends a short distance to the rear thereof, then curves upwardly and forwardly at '53, then slopes downwardly into contact with the top of the shell 3!, the arrangement being such that the spring will be placed under tension when the yoke is moved forwardly about the pivotal axis of the lever. The actuating means for moving the filter supporting device against the action of the spring may take various forms. In the preferred construction it comprises a block 54 slidably mounted in a longitudinal slot 55 in the upper Dart of the body member and having an external part or finger piece 56 slidably supported on the body member by which it may be moved. Secured to the inner side of the slide block 54 is a strip of resilient metal 57 having its forward end bent downwardly and rearwardly above and preferably in contact with the curved rear portion of the spring 52, as shown at 58. The rear end of this lower portion 59 is turned downwardly so as to engage the curved rear end of the spring when the slide block '54 is moved forwardly and to thus rock the yoke 5| about its axis against the action of the spring 52 and move the filter disk into line with the light opening 33. The resilient strip 5'! is provided with an outwardly extending projection 50 so arranged that when the slide block is in its rearmost position the projection 60 will extend into the slot 55 and engage the front wall thereof to yield-ably resist the forward movement of the slide block. The rear portion of the resilient strip is likewise provided with a projection 6| arranged to extend into the slot when the slide block has been moved to its foremost position and thus yieldably retain the filter in its operative position.

The lamp I3 may be connected with an exterior source of current and the flow of the current to the lamp controlled in any suitable manner. In the present instance, a frame 62 is removably mounted in the rear portion of the body member and is retained therein by clips 63. The lamp socket I2 is mounted in and insulated from the front member 64 of this frame. Mounted in the rear portion of the frame and rigidly secured thereto is a rheostat which comprises a cupshaped element 55 carried by the frame and a rheostat winding 56 mounted in and projecting beyond the front edge of the cup-shaped element. The movable member 6'! of the rheostat is in the form of a yieldable finger which is carried by and electrically connected with a shaft 68 which is rotatably mounted in the frame 62 and projects rearwardly beyond the same where it is connected with a rotatable knob 69. As shown in Fig. 6 the contact finger 61 projects from a substantially circular plate I!) which is mounted on the shaft and which is provided with an arcuate slot H to provide the desired yieldability in the finger. One end of the rheostat winding 66 is connected by a conductor bar 12 and a short flexible conductor or jumper 13 with the cylindrical casing of the lamp socket. Mounted on and extending rearwardly from the front member 64 of the frame is a contact member 14 and a spring T5 is connected with the contact member and extends across the rear end of the lamp socket for yieldable engagement with the central contact of the lamp base. Both the contact member 64 and the spring 15 are insulated from the frame. Mounted in the body member near the rear end thereof is an arcuate insulating block 16 which carries two'contact members I! and 18 which project into the body member and are so arranged that when the removable frame 52 is inserted in the body member the con tact H will engage the contact member 14 and the contact member 18 will engage a part of the frame, in the present instance the bar i9, which is electrically connected with the shaft which carries the movable contact finger 61. The contact member H is carried by and forms a part of a conductor bar 83 mounted in the lower portion of the block 16 and having a lug 8! which extends into an opening 82 in the lower wall of the body member. A tubular element or connector 83 is arranged beneath the opening 82 and is provided with an arcuate member or shoe 84 which extends about the lower portion of the body memher and is rigidly secured thereto by screws 85 and 86, which also extend through insulating block 16 and secure the latter to the body memher. The interior of the tubular element 83 is lined with insulating material 81 and slidably mounted therein is a block 88 provided with a central contact member 89 which is connected by a flexible conductor 90 with the lug 8! of the conductor bar 8!). A spring '9! urges the slide block 88 toward the outer end of the tubular; element. The conductor cable 32 has secured to the end thereof a tubular element 93 adapted to project into the lower portion of the tubular element 83 and having mounted therein a central contact member 94. A collar or coupling member 95 is screw threaded onto the lower end of the tubular element 83 to connect the cable therewith and moves. the contact member 94 into engagement with the contact member 89 and presses the same inwardly against the action of the spring i so as to provide firm engagement between the two contacts. The contact member 94 is connected with one conductor, 90, of the cable and the other conductor, Sl, of the cable is turned over against the wall of the tubular element 93 and secured in electrical contact therewith. The metallic tubular elements, nut and screw 85 electrically connect:the conductor 0! with the contact member #8 which is held in place by and is in electrical contact with the screw 86. Thus the conductors of the cable 92 are electrically connected respectively with the cylindrical wall of the lamp socket i2 and with the contact in the base of the lamp and the flow of the current is controlled by the rotation of the knob 80.

In Figs. 7 to 10 there is shown another e.. bodiment of the invention in which the tubular structure comprises a relatively short tubular body member I00 and a non-rotatable tubular lens supportin element ML of substantially t same diameter as the body member and ar ranged in axial alinement therewith. A tubular adjusting device I02 is rotatably supported on the body member and lens supporting member and is connected with those members by screw threads I03 and I04. One of said connections comprises a right hand thread and the other a left hand thread so that the rotation of the adjusting device on the body member and the lens supporting member will cause the adjusting device to move axially with relation to the body member and will cause the lens adjusting member to move with the adjusting device and also to move axially with relation thereto in the same direction as the adjusting device moves. The lens supporting member may be held against rotation in any suitable manner and, as here shown, a substantially cylindrical key element I85 is mounted in the tubular structure and extends into both the body member and the lens supporting member. The body member is provided at its forward end with an inwardly extending circumferential rib or flange IEBB having notches I01 forming keyways, and the lens supporting member is provided with longitudinal grooves I08 which also form keyways. The key'member I is provided with exterior longitudinal ribs I09 and is also provided at' its rear end with a circumferential external rib or flange H0. The ribs I09 are slidably mounted in the keyways l0? and. I00 so that the key element is held against rotation and in turn holds the lens supporting member against rotation. The key element is connected with the adjusting device I02 for axial movement therewith and, in the present instance, it is provided with a circumferential groove HI into which extend a plurality of pins I I2 mounted in openings in the adjusting device and retained therein by a snap ring I I3. The ribs I 96 and I I 0 limit the forward movement of the key element with relation to the body member thus positively interrupting the rotation of the adjusting device and preventing further movement of the lens adjusting device. Means are provided for sup porting a light filter in front of the lens I l t which is carriedby the lens supporting member. The

filter preferably comprises a disk II5 of trans.- lucent material, such as glass or suitable plastic material. This disk is mounted in an annular holder IIB having a portion of reduced diameter adapted to extend into the tubular lens supporting element in front of the lens. Springs II'I connected with the inner edge portion of the holder extend outwardly between the small diameter portion of the holder and the lens supporting member and are provided with recessed portions II8 to engage projections IIQ on the lens supporting member. Push buttons I20 are slidably mounted in the forward portion of the holder IIS and are connected with the springs IIB to depress the same and release the filter holder for removal.

A lamp I2! is supported by the body portion and extends into the tubular key element. The means for connecting the lamp with a source of current and for controlling the flow of current to the lamp may be similar to those above described or of any suitable character and are not here shown. To eliminate stray rays of light from the lens H4 and the projected beam the ke element is provided with an inwardly extending flange E22 surrounding the lamp which serves to prevent the light being reflected onto the lens from the inner surfaces of the parts in the rear of the flange. An annular shield I23 carried'by the forward portion of the key element has a central opening approximatin the diameter of the lamp and prevents the forward reflection of light from the adjacent surfaces of the key member and its flange. A conical shield I24 is mounted on the lens support adjacent the lens and the apex of the cone is cut away to provide a light opening and this shield serves to prevent the reflection of light onto the lens from the adjacent surfaces within the device. The lens is mounted in the lens support a substantial distance from the, forward end of the latter so that this forward end also constitutes a shield which serves to eliminate stray rays of light from the lens.

While I have shown and described certain embodirnents of my invention I wish it to be understood that I do not desire to be limited to the details thereof as various modifications may occur to a person skilled in the art.

Having now fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

.l. A light projecting device comprising a tubular body member having an internal screw thread adjacent one end thereof and having means to support a, lamp, a tubular lens supporting member extending into and spaced from the threaded portion of said body member and having an external screw thread, a lens carried by said supporting member, an annular adjusting device arranged between said members and having exterior and internal screw threads engaging the threads of the respective members, a tubular member supported in said tubular structure in line with said lamp and extending into said tubular lens supporting member and having in that end thereof adjacent said lens a relatively small light openin in axial alinement with said lens, and a plurality of collecting lenses arranged in said tubular element to concentrate the light rays from said lamp and transmit the same through said opening to the first mentioned lens.

2. A light projecting device comprising a tubular body member having an internal screw thread adjacent one end thereof and having means to support a lamp, a non-rotatable axially movable tubular lens supporting member having a portion to extend into the threaded portion of said body member in radially spaced relation thereto, and having an external screw thread, a lens carried by said supporting member, an annular adjusting device arranged between said members and having exterior and internal screw threads engaging the threads of the respective members, and a stop fixed with relation to said body member, said supporting member having a part to engage said stop and limit the outward movements of said supporting member and said adjusting device the several screw threads being of such length and so arranged that no part of said threads will be exposed by the movement of said lens supporting member to the outer limit of its adjustment.

3. A light projecting device comprising a tubular body member having an internal screw thread adjacent one end thereof and having means to support a lamp, a non-rotatable axially movable tubular lens supporting member having a portion to extend into the threaded portion of said body member in radially spaced relation thereto, and having an external screw thread, a lens carried by said supporting member, an annular adjusting device arranged between said members and having exterior and internal screw threads engaging the threads of the respective members, and a stop fixed with relation to said body member, said supporting member having a part to engage said stop and limit the outward movements of said supporting member and said 10 adjusting device said adjusting member and said body member having smooth cylindrical contact surfaces extending outwardly beyond the threaded portions thereof, said adjusting device and said lens supporting member having smooth cylindrical contact surfaces extending outwardly beyond the threaded portions thereof, said cylindrical surfaces bein of such axial lengths that none of said screw threads can be exposed by the adjustments of said lens supporting member.

PAUL F. EARLY.

REFERENCES CITED The following references are of record in the file of this patent:

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